HOW TO USE THIS ONLINE MAGAZINE
by clicking the arrows at the side of the page.
by clicking anywhere on the page. A slider will appear, allowing you to adjust your zoom level.
and move the page around when zoomed in by dragging the page.
and return to the original size by clicking on the page again.
by entering text in the search field and click on "In This Issue" or "All Issues" to search the current issue or the archive of back issues
a PDF of this magazine.
by clicking on thumbnails to select pages, and then press the print button.
a page via email, Facebook, Twitter and more.
TO VIEW PREVIOUS EDITIONS
, click the
button at the bottom of the screen.
Beyond the Bale : September 2010
September 2010 BEYOND THE BALE 24 WOOL PRODUCTION One of Australia's largest sheep flystrike research projects -- the five-year AWI-funded Breeding for Breech Flystrike Resistance project -- has concluded, finding that Australia does have the genetics to produce sheep that are highly resistant to flystrike. In the project more than 6000 sheep, bred from genetic resource flocks from trial collaborators and commercial industry sires, were monitored at Mt Barker in Western Australia and at Armidale in NSW. In line one, sires and dams that exhibited the desired characteristics (such as bare breech and plain bodied) were selected to breed for resistance, while in line two only sires were selected on the indicator traits (to demonstrate progress in a commercial flock). The third line comprised of unselected sheep. Half the sheep in each of the three selection lines were mulesed and half were unmulesed. Dr Johan Greeff, a senior geneticist with the Department of Agriculture and Food WA who oversaw the Western Australian research, says it was apparent early in the trial there were huge differences in breech strike between sires. Only 2.5 per cent of the progeny of the most resistant sire were struck, compared to 102.9 per cent of the most susceptible sire's progeny. By assessing the traits in the sires used in the Mt Barker flock it was established that, on average, "one out of about every 10 sires would be relatively resistant". While there were huge differences between sire progeny groups in breech strike resistance, dags was the only trait FAST FACTS l Australia has the genetic resource to produce sheep that are highly resistant to flystrike. l However, there are huge differences in breech strike susceptibility between sires. l Breech wrinkle, breech cover and especially dags explain the largest differences between the highly susceptible and resistant sires. FAST FACTS l The SkintractionTM intradermal technology reduces wrinkle and increases the bare area around the breech and tail of sheep. l The system is designed to cause skin contraction without an open wound. l Subject to approval by the APVMA, the system is potentially on track to be commercially available during 2011. which appeared to make a contribution in differentiating between animals for breech strike in a low wrinkle flock in a winter rainfall region, with very small differences for the other indicator traits. In winter dag prone areas, it appears dags are the more dominant factor in breech strike than other indicator traits. Dr Jen Smith, the leader of the NSW research based at CSIRO Livestock Industries in Armidale, found similar results in the summer rainfall dominant regions. In the NSW flock, the progeny of the most resistant sire had a breech strike incidence of only three per cent, compared to 79 per cent for the most susceptible sire. Dags, breech wrinkle and breech cover explained the largest differences between the highly susceptible and resistant sires. The research also found it was genetically possible to breed breech flystrike resistant sheep which also had good fertility, fleece weight, body weight and fibre diameter. More information: www.wool.com/flystrike Following extensive trials, the SkintractionTM system -- an alternative to conventional sheep mulesing -- is potentially on track to be commercially available during 2011, subject to approval by the Australian Pesticides and Veterinary Medicines Authority (APVMA) which is evaluating the technology. Peter St Vincent Welch, the R&D director of Cobbett Technologies Pty Ltd, says validation of 2009-10 trial results are underway and a registration application had been made to the APVMA. The team from Cobbett Technologies and a dedicated group of contractors, scientists, engineers and technical advisers have spent five years developing the formulation and application system. The procedure involves the treatment of skin and wrinkle in the breech and tail region of lambs resulting in stretching the wool-free area. The formulation, including Sodium Lauryl Sulphate (commonly found in shampoos and cosmetics) and benzyl alcohol, is administered to the breech area by a modified Pulse Needle-free applicator. The SkintractionTM process is being evaluated on lambs and weaners using standard lamb marking cradles. In stage one, nine field trails and a CSIRO welfare trial were conducted in 2008-09. Stage two field trials are nearing completion, concluding with the assessment of breech and tail bare area and wrinkle score later this year. The effectiveness of the treatment cannot be fully assessed until six months after SkintractionTM is applied. These field trials have involved commercial farm flocks at various locations in NSW optimising the applicator settings. Stage three is underway to confirm the optimal applicator settings on a range of sheep types and to evaluate application of the SkintractionTM system by a number of mulesing contractors. Peter says this stage was about "fine tuning and getting it right", by improving speed of treatment (currently 10 per cent slower than other methods), improving tail results and assessing the impacts of variability on results from factors such as age, genetics and environment. It is planned the SkintractionTM system will be available to woolgrowers via a license structure (including contractors) when the final R&D stage is successfully completed. More information: www.wool.com/flystrike www.cobbett.com.au SkintractionTM on path to commercialisation Good genetics for flystrike resistant sheep